The concomitance of sand production with hydrocarbon production from subterranean formations is a well known problem. In many types of formations from which hydrocarbon fluids are produced, fine sand particles are concomitants. The concomitant sand particles include both load-bearing solids which are part of the mechanical structure of the formation and fine solids, associated with formation fluids, which are not part of the formation structure. Such particles exhibit a natural tendency to attach to the exposed formation faces and inside the production tubing and other down-well equipment and accumulate, building up packed, cohesive masses at the sites of attachment. This process is known as sand packing. When enough of the particles have so accumulated, flow of fluids produced from the formation may be restricted by the packed sand, or the packed sand aggregates may break off and, if sufficiently large, either settle to the bottom of the well causing sandup, or, if entrained in the fluid traveling up the well, plug the well at a restricted flow location. In either case, hydrocarbon production is impaired, requiring well cleanout and possible formation damage.
The three basic types of sand control techniques heretofore known include drag force reduction, mechanical methods and formation consolidation. Frictional forces of the fluid moving through the formation causes sand movement. Sand movement can be reduced by increasing the flow area, as by providing large perforations, increasing the perforation density or fracturing the formation. Alternatively, the drag forces can be reduced by reducing the fluid production rate. Mechanical sand control techniques include gravel packing or installation of sand screens or a slotted liner. Formation consolidation involves the injection and uniform precipitation of a resin in the sand near the well bore. Many of these techniques are expensive or have applications limited by the type of formation. In addition, even when these techniques are employed, fines are almost always produced. If such fines are not produced, they can eventually block the flow channels in the formation, necessitating expensive remedial measures.
Another approach to treating subterranean formations has involved the injection of cations into the formation to prevent the swelling of clays therein. For example, in U.S. Pat. Nos. 4,374,739, 4,366,074 and 4,355,071, there is described the treatment of clay-containing formations with polycationic polymers including alkyl polycationic polymers, heteroaliphatic polycationic polymers containing rings and pendent polycationic polymers. As described in U.S. Pat. No. 4,393,939, similar cationic polymers have been included in well drilling and cementing fluids to minimize the destabilizing effects due to the water contained in such fluids which penetrates into the formation. Similar treatment of a formation with a solution of an oxygenated polyamine, a reaction product of dimethylamine and epichlorohydrin, is described in U.S. Pat. No. 4,158,521. Formation treatments with solutions of coordination compounds of metals with alkyl polyamines are described in U.S. Pat. No. 2,947,360. Stabilization of the producing formation in the vicinity of the borehole or by means of stabilizing agents added to a waterflood, as with the aforementioned sand control techniques, cannot totally eliminate production of the fine particles associated with the formation fluids produced from the untreated portion of the producing formation.